Go 1.0.2 was released late last night.

It's a bunch of bug fixes, including some nasty ones with hashes. It's completely backwards compatible with go1.0.1 and go1, so there's no reason not to update:

cd $GOROOT
hg pull
hg update -r go1.0.2
cd src
./all.bash

And you're done! You'll probably have to update some packages along the way. It will complain about how it was expecting a package for go1 or go1.0.1, which just means you need to recompile.

Now get back to programming.